Journal: Science Advances

Article Title: A nanonewton force sensor using a U-shape tapered microfiber interferometer

doi: 10.1126/sciadv.adk8357

Figure Lengend Snippet: A schematic diagram of ( A ) experimental setup of the AFM calibration sensing system. BBS, broadband optical source; APD, amplified photodetector; DAC, data acquisition card; PC, personal computer. ( B ) Before contact between the AFM tip and fiber. ( C ) AFM tip slightly deforms after the probe contacts the U-shape fiber section. ( D ) SEM images of a typical U-shape tapered microfiber interferometer: (a) U-shape fiber section, (b) partially enlarged image of the U-shape fiber section (diameter, 4.222 μm), and (c) microscope image of the tip in contact with the U-shape tapered fiber. ( E ) An example of an optical microscope image of a fiber taper section of one of the U-shape tapered fibers used in the experiment.

Article Snippet: From , the light from a broadband optical source (S5FC1550P-A2, Thorlabs) propagates through the single-mode–tapered-multimode–single-mode (STMS) fiber structure and is then collected by an Indium gallium arsenide (InGaAs)–amplified photodetector (InGaAs-APD; Thorlabs: PDA10CS-EC, 700 to 1800 nm), which converts the optical signal to an electrical signal, connected to a data acquisition card (MC Measurement, USB-1608FS-Plus), which, in turn, is connected to a personal computer (PC).

Techniques: Amplification, Microscopy